Process for producing polymaleimide

Abstract

A process for producing a polymaleimide which comprises reacting an aromatic dialdehyde with 2 to 60 moles, per mole of the aromatic dialdehyde, of aromatic amine represented by the formula (I): <IMAGE> wherein X is a hydrogen atom, a halogen atom or an alkyl or alkoxy group each having 1 to 4 carbon atoms to obtain a polyamine, reacting the polyamine with maleic anhydride to obtain a polyamide acid, and dehydration-cyclizing the polyamide acid to obtain a polymaleimide.

What is claimed is: 
     
       1. A polymaleimide prepared by a process which comprises reacting an aromatic dialdehyde of the formula (II): ##STR16## which may be substituted with one or more halogen atoms and alkyl groups; with 2 to 60 moles of an aromatic amine per mole of the aromatic dialdehyde to obtain a polyamine: wherein said aromatic amine is represented by the formula (I): ##STR17##  wherein X is a hydrogen atom, a halogen atom or an alkyl or alkoxy group each having 1 to 4 carbon atoms; and   reacting said polyamine with maleic anhydride to obtain a polyamide acid to obtain a polymaleimide.   
     
     
       2. A polymaleimide prepared by the process of claim 1, wherein the polymaleimide is represented by the formula: ##STR18## where X's, which may be the same or different, each is a hydrogen, a halogen atom or an alkyl or alkoxy group each having 1 to 4 carbon atoms. 
     
     
       3. A polymaleimide prepared by the process claimed in claim 1, wherein the aromatic amine is a compound selected from the group consisting of aniline, toluidine, chloroaniline, bromoaniline, ethylaniline, butylaniline, anisidine, and phenitidine. 
     
     
       4. A polymaleimide prepared by the process claimed in claim 1, wherein the aromatic dialdehyde is selected from the group consisting of 1,2-benzene dialdehyde, 1,3-benzene dialdehyde, and 1,4-benzene dialdehyde.